We're happy to announce that the YouTube Mobile Application for Windows Mobile and Symbian S60 devices is now available in five new languages. We now support users with localised content in Brazilian Portuguese, Polish, Russian, Swedish, and Czech. This brings the total number of languages the app supports to 12.

YouTube's Mobile Application makes it easy to quickly load and watch high-quality YouTube videos on your mobile phone, even in areas with poor coverage. To get the update or to try the app for the first time, simply visit m.youtube.com/app via your phone's browser.

We'd love to get your feedback, so visit our forum if you have questions or want to chat about YouTube mobile.

With around 400 people slated to attend and events spanning three days, this weekend’s Summer In The City Gathering in London looks like being an event to remember. Today, we spotlight four videos providing details of what to expect -- as well as looking forward to what the weekend has in store.

We wish everyone who attends a great weekend and fear not: if you can’t make it to SITC in person, one thing you can rely on is that many of the festivities will be captured on camera. We will run a round-up post on the blog once the videos appear.

Last year, to mark Peace Day -- a United Nations-sanctioned day of global non-violence and ceasefire held on September 21 -- the Peace One Day charity helped persuade Taliban forces to lay down their arms for the day, making it possible for 1.6 million Afghan children to be immunised against polio.

This year, to commemorate the 10th anniversary of the effort to make peace a reality, YouTube is partnering with Peace One Day and actor Jude Law to spread the message of Peace Day to an even wider audience through the "My Take On Peace" contest. All you have to do to participate is upload a video to www.youtube.com/peaceoneday telling the world what you'll do to create peace on September 21. The winner will receive a new HD camera and get the chance to participate in a workshop with award-winning film-maker Jeremy Gilley. Find out more about the programme from Jude Law, here:

The deadline to submit your video is September 30, but entries submitted before September 21 will have the opportunity to be showcased on YouTube and in the annual Peace One Day Music Concert, which, last year, was viewed by a television audience of more than 250 million.

Upload your video now to www.youtube.com/peaceoneday and show us how you're promoting peace and changing lives.

What will watching video be like a few years from now? That's a question that we ask ourselves a lot here at YouTube. In a recent article in Forbes magazine, we shared a few ideas that we've been kicking around. We wanted to share them with you, too, as well as hear your ideas.

When pondering the future of video, these are some of the questions we ask ourselves:

• How long will people primarily use computers to interact with video? How quickly will they move to their televisions or mobile phones?

• What are new and better ways that will help people discover great videos to watch? What new recommendations can search provide? What about recommendations based on like-minded people? What are your friends and family watching?

• How might we allow people to organise YouTube for themselves? How can the experts in our community help us curate YouTube's massive collection?

In thinking about these questions, we've come to realise that YouTube's design needs to evolve to answer them. We want to find innovative and useful ways to surface recommendations to you, and we'll need to create the breakthrough tools that empower you to take centre stage in this role.

The YouTube User Experience team uses storyboards to visualise ideas and kick off discussions about new products that will keep YouTube on the forefront of video technology. In the examples below, we used a nifty application called Comic Life that makes storyboarding fast and easy. These are snippets from two storyboards/scenarios that we used internally to talk about the YouTube of the future:

Those are just some of the ideas that we have been discussing. It's hard to predict the future, but it's one of the most fun and interesting parts of our job.

What do you think the future of video will hold? What do you want to see us do in one, two, or even five years? Share your thoughts and ideas in the comments section below. We look forward to hearing from you.

Sometimes it happens. You've read the Community Guidelines, you think you understand the rules, and you upload videos that you believe comply with them. Then one day you receive a message from us informing you that one of your videos has "been disabled for violation of the YouTube Community Guidelines."

"Huh?" you ask yourself. "What's the connection between the Community Guidelines and my video?" Starting today, we'll help answer that question by including tips from the Community Guidelines in the messages we send you if we take down one of your videos.

For example, you post a video that features nudity. When it gets flagged by the YouTube community and removed by our staff, you'll receive this reminder: "Most nudity is not allowed on YouTube, particularly if it is in a sexual context. Videos that are intended to be sexually provocative are also generally not acceptable for YouTube. There are exceptions for some educational, documentary and scientific content, but only if that is the sole purpose of the video and it is not sexually gratuitous."

We think of this as "just-in-time" learning to help you make and upload videos that stay up on the site for the world to see.

Do small changes make a big difference? In the world of landing pagetesting, they certainly can. A few weeks ago, we ran one of the largestmultivariate experiments ever: a 1,024 recipe experiment on 100% of ourUS-English homepage. Utilising Google Website Optimizer,we made small changes to three sections on our homepage (see below),with the goal of increasing the number of people who signed up for anaccount. The results were impressive: the new page performed 15.7% better than the original, resulting in thousands more sign-ups and personalised views to the homepage every day.

Below is a screenshot of the homepage before the test and the three sections we focused on:

And here are examples of various fonts, messages, and colors we tested:

Section 1: (The words "Sign Up" were put in all caps)

Section 2: (We placed these bubble messages to the left of the word "Sign Up")

Section 3: (We experimented with these different banners in that area)

While we could have hypothesised which elements result in greater conversions(for example, the colour red is more eye-catching), multivariate testingreveals and proves the combinatorial impact of differentconfigurations. Running tests like this also help guide our designprocess: instead of relying on our own ideas and intuition, you have abig part in steering us in the right direction. In fact, we plan onincorporating many of these elements in future evolutions of ourhomepage.

You may notice something looks a little different about our masthead (top navigational area on the homepage) today, and that's because we've done a bit of housecleaning. We've streamlined and simplified the design to focus on the primary experience of YouTube: watching a video. The left side is dedicated to exploration: finding videos to watch through search and browse. The right side is all about organisation of the videos that matter most to you: your subscriptions, your recent viewing history, and your own uploads.

A few features have been removed from this area, to keep it as clean and functional as possible. Unless you have items in your Quicklist or Inbox, they will not appear on the homepage, and the country and language pulldown menus, once at the very top of the page, are now at the bottom.

Next up, we'll be focusing on giving you the controls to make the masthead more personalised.